The call for speakers is open through midnight on April 10, 2009, so get busy submitting those abstracts! Work hard on the title and description, make it something that seems interesting and compelling for attendees. Expect the competition to be fierce and if you don't get selected, come to the Summit anyway and work on making a better pitch for the 2010 Summit. You may find my notes about growing new speakers to be useful (and unofficial!).
On a related note, not quite a year ago I wrote some notes about being accepted as a speaker for the 2008 Summit and thinking about a couple friends that weren't selected. At the time I was leaning towards inviting one or two people to co-present with me, but instead I've decided not to submit a session. Part of that is wanting to give someone else a chance, part of it is acknowledging that between my duties at the Summit as a Director plus my involvement with the PASS Ambassadors and the networking events I'll have a fully loaded agenda.
Not an easy decision, but the right one for this year.